In one conventionally known configuration as a technique for improving an engine output, intake air is compressed by a turbocharger and the resultant compressed intake air is supplied to an engine (turbocharging). This configuration has been widely used for engines in automobiles and the like. Generally, a turbocharger includes: a rotational shaft; a turbine wheel provided on one end side of the rotational shaft; and a compressor wheel provided on the other end side of the rotational shaft. When the rotational shaft rotates at high speed with exhaust energy of the exhaust gas acting on the turbine wheel, the compressor wheel provided to the other end side of the rotational shaft compresses the intake air.
The rotational shaft of the turbocharger is rotatably supported by two journal bearings including: a compressor-side journal bearing provided on a side closer to the compressor; and a turbine-side journal bearing provided on a side closer to the turbine. These two journal bearings are supplied with lubricant oil. Patent Document 1 discloses an example of such a bearing device for a turbocharger.
The bearing device disclosed in Patent Document 1 has, as illustrated in FIG. 1 and FIG. 2 in Patent Document 1, a partition (denoted with reference numeral 34) formed to prevent collision between lubricant oil (denoted with reference numeral LO) flowing from a turbine-side oil discharge path (denoted with reference numeral 32) and lubricant oil flowing from a compressor-side oil discharge path (denoted with reference numeral 33). The partition is formed as a vertical wall extending between an oil discharge port (denoted with reference numeral 21) and an outer circumference portion (denoted with reference numeral 38) supporting an oil discharge port (denoted with reference numeral 20) below a bearing chamber (denoted with reference numeral 3).